砂砾岩地层三维地应力场研究

以西部某地区砂砾岩储层为研究对象,基于丰富的压裂改造资料、地球物理测井资料,分析深部地层实测地应力的大小与方向,建立了适用于砂砾岩储层的地应力评价模型并计算地应力单井剖面.在此基础上,利用地震构造模型构建合理的三维空间数值模型,以单井地应力为基本约束,利用有限元法对工区现今三维地应力场进行反演.研究结果表明:工区地应力整体处于压应力作用下,表现为西北向东南方向逐渐增大的趋势.受断裂发育及次级构造影响,断裂带内3个主应力显著降低,断裂边缘和端部存在应力激增带.地应力方位整体近E-W,受断裂和局部构造发育的影响,局部地应力方向发生偏转.

Study on the in-situ stress field in glutenite formation

Taking the rock of the sand-conglomerate reservoir in an area as the study object, we identified the in-situ stress and its direction through the hydraulic fracturing operation and geophysical logging data(FMI, Sonic scanner). The in-situ stress logging models for glutenite formation were established to calculate the stress longitudinal profile. In the light of this, the 3D numerical model was developed by tectonic model based on seismic data and then the in-situ stress distribution characteristics were studied by numerical simulation of finite element method, which were under the restriction of the measured stress data. The results indicated that the in-situ stress field was under the condition of compressive stress, which showed its ever-growing trend from northwest to southeast. Affected by faults and secondary structure, both horizontal and vertical principal stress in fracture zone decreased dramatically. Besides, there was high stress on the edge of fracture. The direction of horizontal maximum principal stress is E-W, but it was deflected due to the influence of faults and structure locally.